Hitachi Koki Co., Ltd.

Hitachi, Ltd.

Mitsugu Asano

Takashi Yoshida

Fumio Takeda

Tsutomu Omine

Susumu Saito

Hideki Tanaka

Kimio Tatsuno

Isamu Terashima

Shigenobu Katagiri

Masao Miyasaka

Hiroshi Takahagi

Yoshikazu Ishitsuka

Shoichi Ito

Yoshifumi Homma

Toshiaki Fujieda

Yukio Yamamoto

Masami Ishikawa

Yoshifumi Ono

Akira Igarashi

Hiroya Taguchi

Hirochika Okano

A printing apparatus for effecting printing on a printing medium, comprising a rotatably supported platen roller, a printing head which faces the platen roller and which is designed to allow a printing medium to pass between it and the platen roller, rotary support members arranged on either side in the axial direction of the platen roller and the printing head, a mechanism for rotating the rotary support members, and printing medium retaining devices for continuously retaining the printing medium on the respective outer peripheries of the rotary support members in such a manner that it is movable with respect to the peripheries.

Printing apparatus

A thermal printer wherein a sheet of recording paper is interposed between two drums provided on axially opposite sides of a shaft of a platen roll facing a line-type thermal head and an endless belt mounted on outer peripheries of the drum. One way clutches provided on a shaft of the drum will cause the paper to rotate together with the drums during recording and the recording paper is driven by the endless belt during paper feed and delivery operations to slide relative to the drums. The sheet of paper is fed to a lower portion of an open portion of the drums and is removed from an upper portion of the open portion of the drums so that the feed and delivery of the sheet of paper can be effected upon rotation of the drums in one direction, and the printing operation is started after a detection of a trailing end of the sheet of paper so that the printing operation can be reformed regardless of the length of the sheet of paper immediately after the feed of the sheet of paper.

Multicolor thermal printer recording medium transmission mechanism

An apparatus for driving a thermal recording head having a plurality of heat-generating elements in alignment wherein energy applied to any one heat-generating element is determined on the basis of a recording energy E.sub.p determined on an assumption that both the heat-generating element and adjacent heat-generating elements are energized and also in accordance with a compensation energy E.sub.r for compensating for an energy shortage at the time of non-energization of adjacent elements in actual recording. The recording energy E.sub.p is determined from a target energy EO required for forming a recording dot, heat storage energy E.sub.s already possessed by the element before a current energization thereof and a correction quantity given by a function of the heat substrate temperature T.sub.h, and E.sub.s is stored and updated for each line recording operation in accordance with a function of E.sub.p. The compensation energy E.sub.r is given by a function of the value T.sub.h selected in accordance with the energization/non-energization of the current element and adjacent elements. The amount of energy applied to each heat-generating element is finely and precisely controlled by energization pattern data D1 to D8 of n (e.g., 8) bits for selecting different combinations of durations and positions of energization pulses. There are 4096 heat-generating elements are divided into 16 blocks, and such an energization pattern data serially transferred is rearranged and transferred in parallel to the blocks.

Driving apparatus for thermal head

An apparatus for driving a semiconductor laser for use in a laser-beam printer, in which a laser beam from the laser is deflected so as to scan a light-sensitive drum and a light-sensitive detector placed in the vicinity of one edge of the drum, comprises a first device for determining the operation level for the laser when it scans the drum to record information thereon, a second device for determining the operation level for the laser when it scans the detector to provide a scanning start pulse signal and a controller for controlling the first and second devices so that they are alternately enabled to determine the intensity of the laser beam depending upon whether the drum or the detector is scanned, whereby the intensity of the laser beam is allowed to be adjusted in accordance with the varying light-sensitivity of the drum without fluctuating the instant of generation of the scanning start pulse signal.

Apparatus for driving a semiconductor laser for use in a laser-beam

An improved printing magnet drive device for use in a printing apparatus, such as line printer, is disclosed. The improvement comprises a constant voltage control means in which an output terminal voltage of a transistor is compared with a reference voltage and the comparison result is fed back to the transistor so as to control the output terminal voltage of the transistor to a predetermined value, whereby the voltage applied to the printing magnets is substantially maintained unchanged.

Printing magnet drive device

Growing community of inventors

Ibaraki, Japan

Mitsugu Asano